A while ago I setup sendgrid for my home server to send myself notifications.

When I set it up, protonmail was receiving those emails.

For some reason I’ve stopped receiving them. Doing some testing, I’ve confirmed that sendgrid will receive the SMTP send request from my server, but does not deliver to protonmail. It does however deliver to Gmail address.

I’ve searched, but can’t seem to find how to debug this issue. Any suggestions? Have you seen this issue before?